Lathe-chuck.



v PATBNTBD DE0.1,1903. c. C. HARRIS.

LATHE CHUCK.

APPLICATION FILED PEB. 24. 1903'. y

N0 MODEL.

UNITED STATES atented December 1, 1903.

PATENT` OEEIcE.

LATHE-CHUCK.

SPECIFICATION forming part of Letters Patent N0. 745,346, dated December1, 1903. Application led February 24,1903. Serial No. 144,895. (Nomodel.)

To all whom it may concern,.-

Be it known that I, CHARLES C. HARRIS, a citizen of the United States ofAmerica, residingin the city of Ukiah, county o f Mendocino, State ofCalifornia, have invented certain new and useful Improvements inLathe-Chucks; and I do hereby declare the following to be a full, clear,and exact description of said invention, such as will enable othersskilled in the art to which it most nearly appertains to make, use, andpractice the same.

My invention relates to an improved chuck forA clamping and holding ablock or other piece of mechanism in a lathe, so as to present it to thedrill or other lathe-tool; and it consists of a novel combinationwhereby the chuck-head can be shifted and rendered temporarily permanentwithin the range of its circumference, and thereby bring any pointWithin its circumference in line with the lathetool. It alsohas'anarrangement by which the chuck-head can beindependently rotatedwhen adjusted to either position and by which a circle around any givencenter can be presented to a drill or other tool, all as hereinaftermore fully described.

Referring to the accompanying drawings, Figure 1 represents a front viewof the chuckhead with its converging clamps and showing the eccentrichub and cam-groove in its back piece in dotted lines. Fig. 2 is a sideview showing the chuck-head, intermediate plate, and back piece inplace. Fig. 3 is a rear view of the intermediate part, showing theeccentric hub and the cam-groove. Fig. 4 is a sectional view of theintermediate part, taken through the line no Fig. 3. Fig. 5 is a rearview of the back piece. Fig. 6 is a sectional view of the backpiece,taken through the lines a' z, Fig. 5; and Fig. 7 is a front viewof the chuck, showing the eccentric thrown to its widest position,disengaging the sliding clamp to show its application and construction.

My improved chuck is composed of three parts A B C. The part A is thehead of the chuck, and it has three jaws or clamp-blocks d d d arrangedon its face so as to be moved toward and from its center in the usualman ner of mounting and moving the clamps of a chuck in order to holdthe block or otherfpiece of mechanism to be operated upon. The part B-is the intermediate part, and it is centered posite each other onopposite sides will be] sufficient. Each slide g has a stern 71.projecting from it and passing through a bearing t' on the rim of thehead-piece A. The opposite end of this stem is provided withscrew-threads, and a thumb-nut screws down upon it. By screwing. thesethumbnuts tightly down upon the outer face of the head-piece A theslides g are pressed firmly against the outer rim of the groove, and thetwo parts are bound together as a unit; but by loosening the thumb-nutsthe slides are free to travel in the groove, so that the head-piece Acan rotate upon the intermediate part B. It is advisable to have theslides g loosely secured to the end'of the stems but is concentric withthe center of the hub k. One side of this circular groove is underf out,as shown at Fig. 3, so that it will retain the slide, hereinafterreferred to, and prevent it 4from coming out of the groove except at itsextremities.

The rear part C of the chuck is of the same diameter and circumferenceas the two parts A and B, and it has a circular recess L in its frontface corresponding with the hub lc on the intermediate part B andadapted to fit over and i-nclose it. This circular recess is also placedon one side of the center of the part C, so that when the two partsare-fitted together, with the hub lo entered into the recess or socketL, the rims of the two parts c0- incide. The part B also carries a slidefm. on the opposite side of its center in position to IOO enter and movein the circular groove Z when the part C is rotated upon theeccentricallyplaced hub 7c. This slideispreferablyametal plate, which issecured to the extremity of a spindlep. Thisspindlepasseslooselythroughthe part C, and its outer end is provided with screw-threads, upon whicha thumb-nut r is turned. It will now be seen that when the center ofthepart C is coincident with the center of the part B it can be xed in thisposition by turning the th umb-nut o hard against the rear face of thepart B, because the pressure of the slide m against the undercut side ofthe groove Z will serve to clamp the two parts together; but byloosening the thumbnut fr, so that the slide can travel Jfreely in itsgroove Z, the part C can be rotated on the eccentrically-placed hub, andthereby carry the center of the part B to a maximum distance from thecenter of the part C, and at whatever position it is set the tighteningof the thumb-nut r will tix it in that position.

The mandrel S, by means ol which the chuck is fixed in the lathe, issecured to the center of the back piece C, as shown at Fig. 2, and whenall the parts are tightened together the whole forms an ordinary chuck,which can be used for centering and turning as a unit, in which case thecenters of all the three parts are coincident; but by loosening thethumb-nuts j so as to allow the slides g to move freely in the groove f,the headpiece A, in which the block or other piece of mechanism is heldby the jaws or clamp d, can be rotated in either direction on the partsB and C, which are still held clamped by the thumb-nut r andfriction-holding slide fm; but when it is desired to shift the centerthe rear nut r is loosened, so as to permit the slide m to move freelyin the circulargroove, and the parts A and B can then be rotated uponthe eccentric hub 7c, so as to carry the center of the head-block A toany position around the hub-center with its circu mference either to theright or to the left, and when it is thus adjusted to a new center thethumbnut Za can be again tightened, so as to temporarily fix it in thatposition. By this means any center can be obtained within the radius ofthe head-piece A of the chuck, and when any of these centers have beenxed the headpiece A can be rotated on the intermediate piece B, so as tobring the lathetool to bear upon an entire circle around the main centerequal to the distance of the new center from the main center of thechuck.

This chuck will be a very convenient tool in lathe-work, for when theblock or other piece to be operated upon is once clamped by the jaws andcentered it can be readjusted to a new center without removing it fromthe jaws.

Having thus described my invention, What I claim, and desire to secureby Letters latent, is-

1. In a lathe-chuck, a circular head-piece having convergingholding-jaws on its front face; a circular block centrally connectedwith the back of the head-piece by a swivel connection; agroovesurrounding the outer rim of the swivel-piece; two o1' more slidesfitted to move in said groove and connected with the outer rim of thechuck and means for clamping said slides against the side of the groovewhereby the swivel piece is stopped from rotating and clamped to thehead-piece, in combination with an eccentrically-mounted back piece,substantially as described.

2. In a lathe-chuck composed of three parallel parts, a circularhead-piece carrying diverging jaws; au intermediate swivel partconcentric to the front part; a hub eccentrically placed on the rearface of the intermediate part; a rear part adapted to fit and rotate onsaid eccentrically placed hub; a groove or channel in the rear face ofthe intermediate part concentric with said eccentric hub, a slideconnected with the rear part and adapted to move in said groove, andmeans for clamping the slide in said groove, substantially as described.

In witness whereof I have hereunto signed Illy lltlll.

CHARLES C. HARRIS. i Witnesses:

A. AsHDowNE, C. N. JONES.

